Trioxane-Derived Stable Solid Electrolyte Interphase Enlightens High-Mass-Loading LiNi _0.5 Co _0.2 Mn _0.3 O ₂ /Li Metal Battery

Next-generation high energy batteries reckon on the ameliorations of electrolyte, which could maintain a dendrite-free lithium-metal anode over extended cycling. Designing a stable solid electrolyte interphase layer on the surface of Li metal is viewed as an effect way to achieve this goal. In this work, trioxane (TXE) is used as a novel co-solvent in commercial carbonate electrolyte (1 M LiPF 6 /EC/DEC/EMC) to promote cycling stability of high-mass-loading (23.2 mg cm −2 ) LiNi 0.5 Co 0.2 Mn 0.3 O 2 /Li metal battery. Due to polymerization induced by PF 5 (decomposed from LiPF 6 ) on Li surface, TXE can be initiated into polymerization, and then the stable composite solid electrolyte interphases on the surface of anode and cathode can effectively protect electrodes. Benefited from the protective interphases, this modified electrolyte significantly improves cycling stability of high-mass-loading LiNi 0.5 Co 0.2 Mn 0.3 O 2 /Li metal battery, which is significantly better than that of benchmark carbonate electrolyte. Impressively, the cell still delivers high capacity retention (68.3% and 55.4%) after 100 cycles at high cutoff voltage (4.3 V and 4.45 V, respectively). In contrast, the cells using 1 M LiPF 6 /EC/DEC/EMC suffer from over charge phenomenon due to the serious lithium dendrites. These fascinating characteristics would make TXE a very promising film-forming co-solvent in developing high-energy-density lithium metal batteries.